Method of making a tubular key construction

ABSTRACT

A tubular key for axial pin tumbler locks which may be integrally and unitarily formed from a piece of tubing with the handle end being formed by a flattening of the tube for a predetermined distance from one end and wherein the lock spindle actuating portion is an integrally formed outwardly projecting protrusion on the tubular shank. There is also disclosed a novel method of making the actuating portion on the key.

I Umted States Patent 1 91 1111 3,886,780 Falk June 3, 1975 [5 METHOD OF MAKING A TUBULAR KEY 1,891,214 12 1932 galk '70 404 x C TR T 2,982,121 5/1961 eorge 70/404 X ONS UC 3,261,540 7/1966 Valbjorn 29/156.4 R Inventor: Morris Falk, Palm p g Cahf. 3,744,286 7/1973 Trainer 70/404 [73] Assignee: Fort Lock Corporation, River Grove, 111. Primary ExaminerC. W. Lanham Assistant ExaminerVictor A. DiPalma [22] 1974 Attorney, Agent, or FirmWolfe, Hubbard, Leydig, [21] Appl. No.: 479,866 Voit & Osann, Ltd.

Related US. Application Data [62] Division of Ser. No. 323,980, Jan. 15, 1973, [57] ABSTRACT abandoned.

A tubular key for anal pin tumbler locks which may 52 US. Cl. 72/324; 70/404; 72/335; be integrally and unitarily formed from a piece of 72 3 7; 72 370 ing with the handle end being formed by a flattening 51 Int. c1 .2 B2ld 53/42 efdte tube for e predetermined distance from one nd 58 Field of Search 72/367, 524, 399, 370, and wherein the lock Spindle actuating Portion is an 72 5; 70 363, 35 7 40 368 integrally formed outwardly projecting protrusion on the tubular shank. There is also disclosed a novel 5 References Cited method of making the actuating portion on the key. UNITED STATES PATENTS 1 Claim 5 Drawing Figures 465,957 12/1891 Willmott 72/370 /d a Z? I I III I 44 l I ill- METHOD OF MAKING A TUBULAR KEY CONSTRUCTION This is a division. of application Ser. No. 323,980, filed Jan. 15, 1973, now abandoned.

DESCRIPTION OF THE INVENTION This invention relates generally to tubular keys for axial pin tumbler locks and more particularly to an improved tubular key construction which may be ofa simple. low cost integral and unitary design including an outwardly extending lock cylinder actuating protrusion.

Axial pin tumbler locks are being used more and more widely for security purposes. principally due to the greater number of possible key combinations available for such lock designs well as the greater difficulty encountered in attempts at picking such locks. An exemplary lock of this type which provides maximum security as well as a virtually pick-proof construction is disclosed and claimed in Patrick M. Trainor, U.S. Pat. No. 3,509,748 assigned to the assignee of the present invention.

Conventional tubular keys that have been utilized with such locks are generally made up of two components, i.e. a flat handle portion and a cylindrical shank which is press fit or otherwise secured to the handle portion. The cylindrical shank is commonly a machined member made from solid rod stock by several cutting operations. These include cutting ofa stepped and slotted portion adjacent the shank end receiving the handle and drilling a central opening forming the hollow tubular portion at the opposite end thereof. The key blank thus formed is a fairly costly item and it is not too uncommon for the handle portion to separate from the shank in use or handling particularly when the key is subjected to very high torques at one time or another. Where the shank has been loosened it can fall off and be lost when the key is carried on a holder passing through an opening usually provided in the handle.

There is disclosed and claimed in Patrick M. Trainor U.S. Application Ser. No. 222,601, now U.S. Pat. No. 3,744,286, assigned to the assignee of the present invention an integral tubular key which eliminates the aforementioned disadvantages of the two piece key. Regardless of whether a multipiece or unitary key is used, it is desirable to have an actuating portion on the key shank to transmit the rotational force applied to the key to the lock cylinder when operating the lock. This actuating portion usually in the form ofa lug slides into a groove formed in the spindle.

The lug disposed on the inside of the tubular key shank presents problems not only with the manufacture of the key, but the groove in the spindle provides a way of applying a torque to the spindle for picking. Also, an additional lug may be required on the outside of the key for easier polarization of the key with the lock.

In another form used, as illustrated in tlie aforementioned U.S. Pat. No. 3,509,748 the key shank has an opening which cooperates with a spring biased ball radially disposed in the casing to project into the annular keyway. Aside from the added cost of manufacture and assembly problems connected with this approach. difficulties have been experienced maintaining the appropriate spring pressure on the ball to keep it functioning properly.

Accordingly, it is a primary object of the present in vention to avoid all of the foregoing disadvantages and provide an improved tubular key construction for use with axial pin tumbler locks which is not only extremely low in cost of production. and maintains the strength and rigidity required of such keys but which includes an otmvardly projecting lockspindle actuating portion. A related object is to provide a tubular key of the foregoing type which may be totally integral and unitary in construction and which may be easily fabricated on a production basis without the necessity of numerous costly machining or fabricating operations.

It is another object to provide an integrally formed tubular key which incorporates provision for precise alignment to enter the keyway.

It is still another object of the present invention to provide a method of unitarily forming a tubular key construction having a lock spindle actuating portion that extends outwardly which is not only more attractive in styling and design than conventionally known tubular key arrangements but is rugged and capable of withstanding rigorous handling and use without falling apart. I

Other objects and advantages of the invention will become apparent as the following description proceeds, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a perspective view of a tubular key incorporating the features of the present invention;

FIG. 2 is a side view of the key of FIG. 1 with a portion of the tubular shank broken away;

FIG. 3 is an end view taken along the line 33 in FIG. 2;

FIG. 4 is a bottom view of the key of FIG. 2; and

FIG. 5 is a perspective view showing the manner in which the key operates with a lock cylinder.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to the particular embodiment shown but intend to cover the various alternatives and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to the drawing, there is shown a completely formed tubular key constructed in accordance with the present invention, indicated generally at 10. The key may be integral and unitary in construction and includes a tubular end portion 12 with central opening 14 therein and a generally flat handle portion 16. The tubular end portion 12 receives the circumferentially spaced notches 18 which are properly combinated for a particular lock to engage and align the axially directed combination pins of the lock when inserted and thereby permitting rotation of the lock cylinder. For details of the integral key, cross reference is made to the aforementioned P. M. Trainor U.S. Pat. No. 3,744,286.

The key blank is produced by flattening a cylinder or tubing adjacent one end for a predetermined distance to form a handle portion 16 which may be easily accomplished with any suitable clamping or press apparatus. The flattened end may then be chamfered or rounded as indicated at 22 to provide a visual manner of identifying reference sides for orienting the key to insert it into the lock. For example, the shorter side 23 may indicate the top of the key while the longer side 24 indicates the bottom or vice-versa. The handle may also be provided with a suitable opening 25 to receive a key ring or the like.

In accordance with the present invention, the tubular shank is provided with an outwardly projecting protrusion 26 for transmitting rotational torque to the lock spindle casing for opening and closing the lock. It also functions to precisely align the key with the keyway. The protrusion 26 which is integrally formed in accordance with the present invention is preferably semispherical or dome-shaped with smoothly rounded surfaces. However, it will be apparent that the protrusion may be square, rectangular or any other desired shape.

In order to form the protrusion 26 according to the method of the present invention, the tubular shank is deformed radially outwardly from the inside of the shank. To this end, in its preferred form, an opening 27 is made radially through the tubular shank on the side opposite to that where the protrusion is to be formed. A punch or other deforming tool may be then inserted through the opening 27 and driven against the inside of the opposite portion of the tubular shank to form the protrusion 26 therein. The deforming operation leaves the hollow portion 28 on the other side of the protrusion 26. (FIG. 2). The formation of the protrusion in this manner produces the desired dome or semispherical shape projecting outwardly on the surface of the tubular key shank. The opening 27 (FIG. 4) on the opposite side of the shank is sufficiently small that it does not detract from the overall strength or function of the key.

LII

Referring to FIG. 5, there is shown a lock spindle 30 of the type which is used with the key 16. The spindle includes a central shaft 32 which at the rearward end is provided with slats 36 that receive the locking lug or other locking member (not shown). Surrounding the spindle is the cylindrical casing 31 affixed to the shaft 32 and defining an annular keyway 34 therebetween. Preferably, a semi-circular groove 38 is formed in the cylindrical casing 31 adjacent the keyway 34 and adapted to receive the key protrusion 26 when the key is inserted into the keyway. This arrangement permits the transmittal or torque from the key through the protrusion 26 to the cylindrical casing 31 via the groove 38, yet with rounded sides of the groove 38 there are no gripping surfaces to apply a torque to the spindle in conjunction with an attempt to pick the lock.

1 claim as my invention:

1. The method of forming a lock actuating protrusion on a formed tubular key having a tubular shank and a generally flat handle portion, the shank being adapted to be inserted in an annular keyway of an axial pin tumbler lock, comprising the steps of forming an opening radially through one side of the tubular key shank and inserting a forming tool through said opening and deforming the opposite side of said tubular shank radially outward to form a generally dome shaped projection on the outer surface of the tubular shank.

l l l 

1. The method of forming a lock actuating protrusion on a formed tubular key having a tubular shank and a generally flat handle portion, the shank being adapted to be inserted in an annular keyway of an axial pin tumbler lock, comprising the steps of forming an opening radially through one side of the tubular key shank and inserting a forming tool through said opening and deforming the opposite side of said tubular shank radially outward to form a generally dome shaped projection on the outer surface of the tubular shank. 